Questions about mask files and stamps

[tama...@gmail.com]

Hi there (Nick), 

I'm exploring using a stamp_db layer and am running into some problems with overlapping stamps not being masked correctly.  The masked areas occlude each other.

I have the mask files created with name bla.mask.tif parallel to bla.pyr.tif.

They are of type Byte, with overviews (pyramidal).  They do have projection and bounds information.  Pixels of 0 indicate no data, and pixels with values indicate data.

The pyramidal tif files are RGBA (4 band), with band 4 being alpha.  They do not have projection or bounds information, so I provide an .ext file for each pyramidal tif.

What I see is that the stamps are not respecting the mask information, that is, what should be transparent in one stamp is instead occluding another stamp.

Do you have any insight into this?  Are the masks incorrect?  Do you have working samples of this kind of stamp file with mask?

Thanks much

Tamar

[tama...@gmail.com]

Hm, I flipped the mask and it is still having the same behavior, which is suspicious.

I am wondering how the stamp_db layer behaves if there is data being added to the query results on the fly?

Perhaps lunaserv is caching part of the query results?  How does it know when to hit the database again?

Thanks

Tamar

[Nick Estes]

That's interesting. Can you send me a copy of one of your stamps &
associated mask so I can look at the files and test it locally?

--Nick

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[tama...@gmail.com]

Unfortunately we cannot post sample files here but will contact you through email.  Thanks for your support.

Tamar

[tama...@gmail.com]

Mystery solved, thanks to Nick's support!  I was writing an 8 bit mask file (uint8), but the documentation states and lunaserv requires that it be a 1 bit mask file.

Since I am using rasterio to create the mask file, I had to make sure to open it with nbits=1.

Thanks Nick!